Carburetion system



Sept. 20, 1966 w. BALL CARBURETION SYSTEM 4 Sheets-Sheet 1 Filed Nov. 24, 1964 Sept. 20, 1966 w. BALL 3,273,550

CARBURETION SYSTEM Filed NOV. 24, 1964 4 Sheets-Sheet 2 24 J26 j 1/; 112 110 164 i Ml 1/6 A/ 70/ 4 A Wm 5w Sept. 20, 1966 w BALL 3,273,550

CARBURETION SYSTEM Filed Nov. 24, 1964 4 Sheets-Sheet 5 J40 J35 45 150 f6 Sept. 20, 1966 w. BALL CARBURETION SYSTEM 4 Sheets-Sheet 4 Filed Nov. 24, 1964 J J M My Z W 5 AM MW V WM flw M m f 7 fr m & Z L 2 i m WV M w g M M m W W m V 5 Z 1 0 2M 3 5 i 32 l 5 0 United States Patent ()flice I 3,273,550 Patented Sept. 20, 1966 3,273,550 CARBURETKON SYSTEM Warren Ball, 1304 N. Gordon St, Hollywood, Calif. Filed Nov. 24, 1964, Ser. No. 413,506 23 Claims. (Cl. 123119) This invention relates to a carburetion system for an internal combustion engine with the four principal purposes of increasing the horsepower of the engine, reducing unburned hydrocarbon, carbon monoxide and nitrogen oxide in the exhaust and providing positive crankcase ventilation for controlling crankcase blowby emission. More particularly the preferred practice of the invention is directed to an accessory assembly that may be easily and quickly installed on an internal combustion engine to provide such a carburetion system.

The invention provides for recycling the blowby fluids from the crankcase to accomplish one of the four purposes and does so in a particular manner that promotes complete combustion and thus achieves the remaining three major purposes of increasing the horsepower, reducing fuel consumption and cleaning up the exhaust from the engine.

Complete combustion of the fuel is attained by three functions inherent in the operation of the preferred embodiment of the invention.

One function is to add an optimum amount of heat to the gas-air mixture in the engine intake. By optimum amount of heat is meant enough heat to promot vaporization of liquid droplets in the moisture without unduly reducing the weight or content of the fluid stream. The heating of the gaseous fluid in the intake of the engine is accomplished by withdrawing high temperature fluid from the engine exhaust, cooling the withdrawn exhaust fluid to a desirable degree, mixing the exhaust fluid with blowby fluid, and then introducing the heated mixture into the engine intake.

A second function of the carburetion assembly is to create turbulence in the intake of the engine. The intake stream is caused to swirl about its axis and the hot mixture of exhaust fluid and blowby fluid is introduced radially into the intake stream at numerous ciroumferentially spaced peripheral points. By virtue of the swirling rotation of the intake stream, the liquid droplets therein are repeatedly deposited on the passage wall by centrifugal force and are repeatedly entrained again with consequent repeated fragmentation and evaporation to make the heated stream completely dry.

The third function of the carburetion assembly is to act automatically to approximate the ideal or stoichiometric air-fuel ratio of fifteen to one in the engine intake at all times. To perform this function the carburetion assembly must, in effect, sense changes in the conditions under which the engine operates and accordingly appropriately vary the rate of introduction of the fluids into the engine intake.

The sensing of the changes in operating conditions is attained by sensing changes in the pressure in the intake of the engine. For this purpose the flow of the hot fluids to the intake is controlled by valve means that responds to changes in the magnitude of the vacuum in the engine intake. A problem that must be met in carrying out this concept resides in the fact that the need for additional fluid in the intake stream does not vary directly with the magnitude of the vacuum. Under some operating conditions of rising vacuum the need for the added fluid actually varies inversely with the magnitude of the vacuum and under other conditions of rising vacuum, the need for additional fluid varies with the vacuum but climbs much faster than the vacuum rises.

A primary feature of the invention. is the concept of solving this problem by employing two valves in parallel to control the addition of fluid to the intake stream. One of the two valves is responsive only to changes in the vacuum in the range of magnitudes that lies below the magnitude of vacuum that prevails when the engine idles. This first valve varies the rate of introduction of the fluid inversely with changes in the magnitude of the vacuum. The second valve is responsive only to changes in the vacuum in a range above the vacuum that exists when the engine idles and the second valve opens at a relatively high rate in response to rising vacuum.

The first mentioned valve is aptly termed the acceleration valve since it controls the introduction of the recycled fluids during acceleration of the engine and during normal load-carrying operation of the engine. If a constant orifice were substituted for the first valve, the rate of introduction of the fluid into the intake would vary directly with changes in the magnitude of the vacuum and consequently would be grossly inadequate under con ditions of relatively low vacuum and grossly excessive under conditions of relatively high vacuum. The acceleration valve provides optimum control by opening to the maximum under conditions of minimum vacuum and progressively closing in response to rise in the vacuum.

The second valve is termed the deceleration valve because its behavior fits the varying need for additional intake fluid in large quantity under particular conditions of deceleration. In conventional carburetion the vacuum in the intake reaches peak values during acceleration and the consequent exceedingly high pressure diiferential across the carburetor results in what is commonly known as carburetor flush, i.e. injection of raw liquid fuel into the intake. The deceleration valve of the present invention corrects this situation by opening abruptly to add fluid to the intake, the pressure in the intake being drastically reduced to avoid any undesirably high pressure differential across the carburetor.

:As will be made apparent, further features of the invention reside in the construction of an accessory assembly for an engine for converting conventional carburetion to the new mode of carburetion. The new structure is characterized by simplicity, reliability and a minimum number of movable parts. In addition the accessory assembly is adaptable to the needs of a wide range of internal combustion engines, such adaptability being accomplished in part by adjustability of the carburetion mechanism and in part by providing interchangeable elements.

The features and advantages of the invention may be understood from the following detailed description and the accompanying drawings.

In the drawings illustrating the presently preferred embodiment of the invention:

FIG. 1 is a perspective view of a conventional automobile engine incorporating a preferred embodiment of the carburetion system;

FIG. 2 is a plan view of an induction unit for installation at the engine intake, the induction unit incorporating the two valves as well as a heat exchanger for controlling the temperature of the recycled fluids;

FIG. 3 is an elevation of the induction unit as viewed along the line 3- 3 of FIG. 2;

FIG. 4 is an elevation of the induction unit as viewed along the line 4-4 of FIG. 2;

FIG. 5 is an elevational view of the induction unit as seen along the line 55 of FIG. 2;

FIG. 6 is a sectional view of the deceleration valve;

BIG. 7 is a sectional view of the acceleration valve;

FIG. 8 is a sectional view of a mixing valve for blending the two recirculated fluids;

FIG. 9 is a perspective view of an annular induction member that is employed in the induction unit;

FIG. 10 is an exploded view of the induction unit; and

FIG. 11 is a graph which summarizes the behavior of the two valves under different operating conditions.

In FIG. 1 illustrating a typical installation of the in vention, a conventional internal combustion engine for an automobile has the usual crankcase 10, a pair of rocker arm covers 12 enclosing spaces in communication with the interior of the crankcase, an exhaust manifold 13, and a dual throat carburetor 14 mounted on the engine intake and equipped with the usual air filter 15. The accessory assembly for converting the engine to the new mode of carburetion includes: what may be termed an induction unit, generally designated 20, for mounting on the intake of the engine on the downstream side of the carburetor 14; a flexible metal conduit 22 for conveying a portion of the exhaust fluid from the exhaust manifold 13 to the induction unit; a second flexible conduit 24, which may be a plastic hose, for conveying blowby fluids from one of the two rocker arm covers 12 to the induction unit and a special breather cap 25 for the oil fill pipe 26 of the engine, the breather cap replacing the usual breather cap and being a one-way cap designed for inlet flow only.

Referring to FIGS. 2 and 10, the principal parts of the 'induction unit 20 include: a heat exchanger 28 which also serves as a mixing chamber and which is equipped with external fins 30 for transferring heat to the ambient atmosphere, the mixing chamber being connected to the two conduits 22 and 24; a valve casing 32; an acceleration valve in the casing having a valve member 34; a deceleration valve in the casing having a valve member 35; a curved pipe 36 for conveying exhaust fluid from the heat exchanger to the deceleration valve; a curved pipe 38 for conveying a mixture of the exhaust fluid and the blowby fluid from the heat exchanger to the acceleration valve; and two annular induction members 40 for connection to the two throats of the carburetor to serve as short longitudinal portions of the engine intake, the induction members being in communication with the acceleration valve and the deceleration valve to introduce fluids therefrom into the intake.

As best shown in FIG. 10, the induction unit 20 includes a unified base structure comprising a shallow rec tangular box-like frame 42 open at the top and bottom -with the heat exchanger 28 mounted on one side of the frame and with the valve casing 3-2 mounted on the other side of the frame. The frame 42 has a suitable aperture 44 to receive recycled gases from the two valves and is further formed with bores 45 at its four corners to receive corresponding machine screws 45a for connecting the upper side of the induction unit to the carburetor and for connecting the lower side of the unit to the engine intake. The box-like frame 42 is covered from above by a top plate 46 having four bolt holes 48 and having two circular openings 50 to register with the two annular induction members 40. In like manner the box-like frame 42 is covered from below by a bottom plate 52 having bolt holes 54 and having circular openings 55 for the two annular induction members 40.

Each of the two induction members 40 seats in a corresponding opening 55 in the bottom plate 52 and is formed with a downwardly directed outer circumferential shoulder 56 (FIGS. 5 and 9) to abut the upper surface of the bottom plate. The two annular induction members 40 are clamped between the two plates 46 and 52 with the upper rim of each annular induction member in abutment with the lower face of the top plate around the margin of the corresponding circular opening 50 in the top plate.

The bolt holes of the induction unit 20 correspond to the bolt holes of a number of different carburetors. The throats of carburetors vary in diameter, however, and it is contemplated that the induction unit may be made adaptable to carburetor throats of different diameters by simply providing annular induction members 40 of different diameters with top and bottom plates 46 and 52 having circular openings of corresponding different diameters. Thus a number of interchangeable sets may be provided, each set comprising a top plate 46 and a bottom plate 50 with two corresponding annular induction members 40, so that an appropriate set may be selected to adapt the induction unit to any particular carburetor among a number of different carburetors.

As best shown in FIG. 9 each of the annular induction members 40 has an outer cylindrical wall 60 and an inner cylindrical wall 62 which are integrally interconnected by a circumferential series of inclined radial vanes 64. The outer cylindrical wall 60 serves as an extension of a barrel of the carburetor, i.e. as a portion of the engine intake and the vanes 64 serve the purpose of causing the stream of intake fluid to swirl violently about its longitudinal axis. The upper rim of the outer cylindrical wall 60 is provided with a series of circumferentially spaced notches 65, there being two notches for each space defined by a pair of vanes 64. The notches 65 serve as peripheral induction ports for directing fluid from the two valves into the intake stream radially of the axis of the stream.

As shown in FIG. 10, an end plate 66 at one end of the heat exchanger 28 forms two inlet ports 68 and 70 for connection respectively to the exhaust fluid conduit 22 and the blowby fluid conduit 24. In like manner, a second end plate 72 at the other end of the heat exchanger 28 provides an outlet port 74 communicating through the pipe 36 with the deceleration valve and a second outlet port 75 communicating through the curved pipe 38 with the acceleration valve.

As shown in FIGS. 8 and 10, the flexible conduit 22 for the blowby fluid is connected to the heat exchanger 28 by a tubular or nozzle-like valve member '76 which extends through the heat exchanger to the region of the outlet port 75 to cooperate with the outlet port to function as a mixer valve for blending exhaust fluid with the blowby fluid for delivery to the acceleration valve. The tubular valve member 76 directs the stream of blowby fluid into the outlet port 75 and creates a venturi action for inducting a portion of the exhaust fluid into the stream of blowby fluid. The tubular valve member 76 is adjustable with respect to its spacing from the port 75 and for this purpose may be mounted in the inlet port 70 in any suitable manner that permits the required adjustment.

In the particular construction shown in FIG. 8, the tubular member 76 has a radial pin 78 that is confined by a longitudinal slot 80 in a guide collar 82 that is anchored in the heat exchanger by screw means 84. Thus the tubular valve member 76 is free for longitudinal adjustment but is keyed against rotation. At the inlet port 70 the tubular valve member 76 is rotatably and slidably embraced by an adjustment bushing 85 having an external knurled flange 86 to facilitate manipulation. The adjustment bushing 85 is rotatably mounted in the inlet port 70 and is held against withdrawal by a suitable split retainer ring 88. The inner circumferential surface of the adjustment bushing 85 is formed with a spiral cam groove 90 which engages a pin 92 that extends radially from the tubular valve member 76. Thus rotation of the bushing 85 by means of its knurled flange 86 adjustably shifts the tubular valve member 76 longitudinally to vary the spacing between the inner end of the tubular valve member and the outlet port 75. It is contemplated that sufficient frictional resistance to rotation of the bushing 85 will be provided to cause the bushing to maintain any rotational position of adjustment at which it may be set.

As shown in FIG. 10, an end plate 94 at one end of the valve casing 32 provides an inlet port 95 for the deceleration valve and an inlet port 96 for the acceleration valve. In like manner a plate 100 at the other end of the valve casing provides an adjustment port 102 for the deceleration valve and an adjustment port 104 for the acceleration valve.

FIG. 6 shows the construction of the deceleration valve with the valve in its maximum open position. At the closed position of the deceleration valve the nose 105 of the deceleration valve member 35 seats snugly in the previously mentioned inlet port 95 of the valve casing. The deceleration valve member 35 is of tubular construction with an axial bore 106 intersecting a diametrical bore 107 to provide a bypass through the valve member through which a minimum amount of flow occurs when the valve member is in its closed position. The inner end of the deceleration valve member 35 is formed with a cup-shaped enlargement which is in sliding engagement with the surrounding cylindrical wall 110 to guide the valve member throughout its range of motion. A variable control chamber 111 that is formed in part by the valve member 35 houses a suitable coil spring 112 that acts in compression between the valve member and a spring seat member 114 to provide a suitable biasing force that continuously urges the valve member towards its closed position. The spring seal member 114 slidingly telescopes into the enlargement 108 of the valve member 35 to form the variable control chamber 111.

It is contemplated that the spring seat member 114 will be adjustable longitudinally for the purpose of adjustably compressing the coil spring 112 as required for adapting the induction unit to the operating requirements of difl'erent engines. Here again a spiral cam arrange- :ment may be utilized for adjustment of the valve seat member 14.

In the construction shown, the spring seat member 114 is slidably mounted in a hollow rotatable adjustment knob 115 having a knurled flange 116. The spring seat member 114 is free to shift longitudinally but is keyed against rotation by a radial pin 118 that extends into a longitudinal slot 120 of a fixed guide collar 122. A second pin 124 extending radially from the spring seat member 114 slidingly engages a spiral cam groove 125 on the inner circumference of the adjustment knob 115. The adjustment knob 115 is rotatably mounted in the adjustment port 102 and is secured therein in a rotatable manner by a split retaining ring 126. It is apparent that the adjustment knob 115 may be rotated to vary the longitudinal position of the spring seat member 114 and thus vary the degree to which the spring 112 is compressed.

It is to be noted that the diametrical bore 107 together with the axial bore 106 places the variable control chamber 111 in communication with the engine intake through the two annular induction members 40 to cause the control chamber to contract in opposition to the spring 112 when the pressure drops in the engine intake. Thus the enlargement 108 of the valve member 35 is, in effect, a movable wall of the control chamber 111 with the valve member connected to the movable wall for actuation thereby. Consequently the position of the valve member 35 varies with the degree of vacuum in the engine intake, the valve member opening in response to rising magnitude of the vacuum. It is to be noted, however, that the coil spring 112 keeps the valve member 35 seated unless the vacuum rises above the vacuum that prevails when the engine idles. When the valve member 35 is in an open position, fluid flows past the nose 105 to reach the engine intake through a radial port 164 in the cylindrical wall 110 and additional fluid flows to the same port through the bypass formed by the axial bore 106 and the diametrical bore 107. When the valve member 35 is in its closed position fluid flow is restricted to the bypass.

The construction of the acceleration valve may be understood by referring to FIGS. 2 and 7. The acceleration valve member 34 has a conical head 130 which cooperates with a conical valve seat 132 formed in a thick wall of the valve casing 32. The acceleration valve member 34 is further formed with a long stem 134 which extends slidingly through a bore 135 into a variable spring chamber 6 136. Inside the control chamber the end of the stem 134 carries a circular valve seat 138 which backs against suitable spring means in a tubular cage or spring seat member 140. In this particular embodiment of the invention the spring means comprises a series of four pairs of opposed Belleville springs 142.

When the engine is in operation the vacuum existing in the engine intake causes exhaust fluid to flow from the inlet port 96 of the induction unit past the valve head as indicated by the arrows in FIG. 7. It is apparent that under these conditions the upstream end of the valve head 130 is subjected to higher fluid pressure than the portion of the valve member that lies on the downstream side of the valve seat 132. Thus the valve member 34 is subjected to a pressure dilferential which continuously urges the valve member towards its closed position in opposition to the pressure exerted by the Belleville springs 142. In the construction shown the valve stem 134 is provided with a stop collar 144 which abuts the wall of the control chamber 136 to limit the closing movement of the valve member at a position where a small radial clearance, say a clearance of 1, of an inch, exists between the valve head 130 and the valve seat 132. Thus the valve member 34 is free to operate between a nearly closed position and a wide open position.

It is contemplated that the tubular spring cage 140 will be adjustable longitudinally to vary the force exerted by the Belleville springs 142 and here again a spiral cam arrangement may be used for such adjustment. The spring cage 140 is provided with a radial pin 145 which is slidable in a longitudinal guide groove 146 in a fixed collar 148. A second pin 150 extending radially from the spring cage engages a spiral cam groove 152 on the inner circumference of a hollow adjustment knob 154. The adjustment knob 154, which is formed with a knurled flange 155, is rotatably mounted in the previously mentioned adjustment port 104 and is secured therein by a split retaining ring 156. Rotation of the adjustment knob 154 shifts the spring cage 140 longitudinally and suflicient frictional resistance is provided to cause the adjustment knob to maintain any position to which it may be adjusted.

A feature of the preferred practice of the invention is the coating of cooperative valve parts with suit-able plastic material that both reduces friction and resists the deposit of material thereon. Teflon is advantageous for this purpose, and especially so because it can withstand relatively high temperatures.

The manner in which the invention functions to serve its purpose may be understood by referring to FIG. 11 which represents a desired pattern of behavior of the carburetion system. When the accessory assembly is installed on an automobile engine, the two valves that control the recycled fluids are adjusted in accord with the magnitude of vacuum that prevails in the engine intake when the engine idles. In the installation represented by FIG. 11, twenty-one inches of vacuum is found to exist when the engine idles. Accordingly, the acceleration valve is adjusted by means of the adjustment knob 154 to reach its minimum open position when the vacuum in the manifold climbs to twenty-one inches. At this minimum open position, as indicated in FIG. 11, the acceleration valve member 34 is spaced A of an inch from a fully closed position, the stop collar 144 abutting the wall of the control chamber 136 and the head 130 of the acceleration valve member being spaced radially & of an inch from the surrounding valve seat 132. At all positions of the acceleration valve member 34 there is continuous flow from the inlet port 96 of the induction unit to the intake along the following path: the annular space between the head 130 of the acceleration valve member and the surrounding valve seat, a lateral passage shown in FIG. 7 between the valve seat and the spring chamber 136, the rectangular aperture 44 (FIG. 10), the interior of the rectangular frame 42, and the ports or notches 65 in the two annular induction members 40.

It is contemplated that the four pairs of Belleville springs 142 will be of different strengths to collapse in sequence in accord with the curve 162 in FIG. 11 and that the four pairs of Belleville springs will be selected result in four check points that determine the curve. It can be seen in FIG. 11 that at one check point the acceleration valve is open by of an inch when the intake vacuum is two inches; at a second check point the valve is opened by 7 of an inch when the intake vacuum is ten inches; at a third check point the valve is opened by of an inch when the vacuum is at sixteen inches; and at the fourth check point the acceleration valve is at its minimum open position of A of an inch when the engine idles with the intake vacuum at twenty-one inches.

As indicated in FIG. 11 the deceleration valve remains closed as long as the vacuum in the intake manifold is below twenty-one inches. If the vacuum starts to rise above twenty-one inches, the deceleration valve responds by abruptly opening and is wide open at a vacuum of twenty-five inches. Thus the deceleration valve, in effect, prevents the vacuum in the intake from rising higher than twenty-five inches which is much below the usual peak value under such operating conditions and which keeps the pressure differential across the carburetor low enough to prevent the injection of raw fuel into the engine intake.

The point in the rising vacuum at which the deceleration valve opens is determined by the longitudinal adjustment of the valve seat member, which adjustment is accomplished by rotation of the adjustment knob 115. Since the control chamber 111 is in continuous communication with the engine intake through the axial bore 1&6 and the diametrical bore 107, the pressure in the control chamber varies with the intake pressure and the opening action of the valve depends upon the characteristics of spring 112. The opening action may be understood when it is considered that a rise in the vacuum in the intake results in a corresponding drop in pressure in the control chamber 111 with the consequent creation of a pressure differential across the deceleration valve which causes the deceleration valve to open in opposition to the pressure of the spring 112. It is to be noted that a minimum amount of flow occurs through the two valves under all conditions because the acceleration valve cannot completely close and the deceleration valve is provided with the bypass which is always open.

It is apparent that the positive ventilation of the crankcase by the conduit 24 under control of the acceleration valve results in the addition of an appreciable amount of air to the blowby fluid to promote fuel combustion. There is reason to believe, however, that the attainment of complete combustion involves more than adding fresh air to the intake stream. Apparently the high temperature processing of the blowby gas before it reaches the intake and the additional processing in the vortex in the intake stream result in complex chemical changes which also contribute to complete combustion of the fuel. In addition the processing avoids the formation of any gums in the intake which might otherwise be created by constituents of the blowby fluid.

My description herein of the preferred embodiment of the invention in specific detail will suggest various changes, substitutions and other departures from my disclosure within the spirit and scope of the appended claims.

I claim:

1. In a system for recycling gaseous fluids through the combustion zone of an internal combustion engine, wherein passage means conveys gaseous fluid from the engine to the intake of the engine, the improvement comprising:

a first valve and a second valve operating in parallel to control flow through the passage means in response to changes in the pressure in the intake,

the first valve being open at relatively low vacuum in the intake and progressively closing in response to rise in the vacuum,

the second valve being closed at a relatively high 8 vacuum in the intake and progressively opening in response to rise in the vacuum.

2. An improvement as set forth in claim 1 in which the first valve responds to a range of changes in the Vacuum below the vacuum at which the engine idles and the second valve responds to a range of changes in the vacuum above the vacuum at which the engine idles.

3. An improvement as set forth in claim 2 in which at least one of the two valves incompletely closes to permit a minimum rate of flow therethrough when the engine idles.

4. In a system for recycling gaseous fluids including blowby fluid through the combustion zone of an internal combustion engine, wherein passage means conveys gaseous fluid from the engine to the intake of the engine, the improvement comprising:

a first valve and a second valve operating in parallel to control flow through the passage means in response to changes in the pressure in the intake,

the first valve being open at relatively low magnitudes of vacuum in the intake and progressively closing in response to rise in the vacuum,

the second valve being closed at relatively high magnitudes of vacuum in the intake and progressively opening in response to rise in the vacuum to higher magnitudes; and

means to cause the fluid in the engine intake to swirl.

5. An improvement as set forth in claim 4 which includes means to preheat the blowby fluid.

6. In a system for recycling gaseous fluid through the combustion zone of an internal combustion engine wherein passage means conveys blowby fluid from the engine to the intake of the engine, the improvement comprising:

said passage means additionally conveying exhaust fluid from the engine to the intake of the engine;

a first valve and a second valve operating in parallel to control flow through the passage means in response to changes in the pressure in the intake,

the first valve being open at relatively low magnitudes of vacuum in the intake and progressively closing in response to rise in the vacuum to higher magnitudes,

the second valve being closed at relatively high magnitudes of vacuum in the intake and progressively opening in response to rise in the vacuum to higher magnitudes;

means to mix a portion of the exhaust fluid with the blowby fluid to raise the temperature thereof; and

means to cause the fluid in the engine intake to swirl.

7. An improvement as set forth in claim 6 which includes means to reduce the temperature of the exhaust before the exhaust fluid is mixed with the blowby 8. In a system for recycling gaseous fluids through the combustion zone of an internal combustion engine, wherein passage means conveys gaseous fluid from the eng ne to the intake of the engine, the improvement comprising:

a first passage and a second passage, each providing communication between the engine and the intake to create a pressure differential in the passage to convey gaseous fluid from the engine to the intake;

a first valve means in the first passage urged to its closed position by fluid pressure differential in the passage;

first spring means opposing the closing movement of the first valve means to cause the first valve means to operate in response to changes in the fluid pressure differential across the first valve means, said spring means being of a strength to permit the valve means to close to a limit position as the rise in the vacuum in the intake of the engine approaches the vacuum that exists when the engine idles;

second valve means in the second passage urged towards its open position by the fluid pressure differential in the second passage; and

second spring means opposing the opening movement of the second valve means to cause the second valve means to operate in response to changes in the pressure differential across the second valve means, the second spring means being of a strength to prevent opening movement of the second valve means until the vacuum in the intake of the engine exceeds the vacuum that exists when the engine idlles.

9. An improvement as set forth in claim 8 which includes means to adjust the stressing of at least one of the two spring means to vary the responsiveness of the corresponding valve means to the corresponding pressure differential.

10. An improvement as set forth in claim 8 in which at least one of the two valve means permit-s fluid flow therethrough at the limit closed position of the valve means.

11. In a system for recycling gaseous fluids through the combustion zone of an internal combustion engine wherein the engine has an intake passage, an exhaust passage, and a confined sp'aced above the oil level to receive blowby fluid, the improvement comprising:

a mixing chamber in communication both with the exhaust passage and with the confined space, the mixing chamber being in communication with the intake passage for vacuum action to draw exhaust fluid and blowby fluid into the mixing chamber for mixture therein and to draw fluid from the mixing chamber into the intake passage; and

valve means to regulate the flow of the fluids to the intake passage in response to changes in pressure in the intake passage.

12. An improvement as set 'forth in claim 11 which includes heat exchanger means exposed to the atmosphere for heat exchange to cool the exhaust fluid.

13. In a system for recycling gaseous fluids through a combustion zone of an internal combustion engine wherein the engine has an intake passage, an exhaust passage, and a confined space above the oil level to receive blowby fluids, the improvement comprising:

a mixing chamber;

passage means connected to the exhaust passage to convey exhaust fluids therefrom to the mixing chamber;

passage means in communication with the confined space to convey blowby fluids from the confined space to the mixing chamber;

a first passage from said mixing chamber to the intake passage;

a second passage from the mixing chamber to the intake passage;

a first valve in the first passage responsive to changes in the vacuum in the intake passage below the magnitude at which the engine idles and adapted for progressive closing action in response to rise in the vacuum; and

a second valve in the second passage responsive to changes in the vacuum in the intake passage above the magnitude at which the engine idles and adapted to open progressively in response to rise in the vacuum.

14. An improvement as :set forth in claim :13 in which said mixing chamber has a relatively high surface exposed to the atmosphere for cooling action on the gaseous fluid in the mixing chamber.

15. In a system tor recycling gaseous fluids through the combustion zone of an internal combustion engine wherein the engine has an intake passage, an exhaust passage and a confined space above the oil level to receive blowby fluid, the improvement comprising:

means forming a first passageway from the confined space to the intake passage for flow of the blowby fluid to the intake passage;

means forming a second passageway from the exhaust passage to the intake passage for flow of exhaust fluid to the intake passage;

a first valve means to control flow through the first passageway and to progressively reduce the flow in response to rise in the vacuum in the intake in a range below the vacuum at which the engine idles;

a second valve means in the second passageway to control flow therethrough and to progressively open from a limit position in response to rising vacuum in the intake manifold in a range above the vacuum that exists when the engine idles.

16. An improvement as set forth in claim 15 which includes means to transfer heat from the fluid in the second passageway to the fluid in the first passageway to heat the fluid in the first passageway.

17. An improvement as set forth in claim 15 which includes means downstream from both of the two valves to divert a portion of the exhaust fluid from the second passageway to the first passageway to raise the temperature of the fluid in the first passageway.

18. An improvement as set fOTlJh in claim 17 which includes means to reduce the temperature of the diverted fluid before it enters the first passageway.

19. In an induction unit of the character described for installation between the carburetor and the intake passage of an engine, which engine has an exhaust passage and a confined space to receive blowby fluid, the combination of:

a structure for mounting on the engine intake on the downstream of the carburetor, and structive including wall means forming a portion of the intake passage with a closed space surrounding the wall means and with the wall means apertured for fluid flow from the enclosed space into the intake passage;

means united with said structure forming two passages outside of the structure with both passages communicating with the enclosed space, one of the said passages being adapted for connection to the exhaust passage of the engine, the other passage being adapted for connection to the confined space of the engine;

a first valve means in one of said passages to control fluid flow therethrough and adapted to close progressively in response to rising vacuum in the intake passage in a range of magnitude of vacuum below the magnitude of the vacuum that exists when the engine idles; and

a second valve means in the other of the two passages to control fluid flow therethrough and adapted to open progressively in response to rising vacuum in the intake passage in a range of magnitudes of vacuum below the magnitude of the vacuum that exists when the engine idles.

24). A combination as set forth in claim 19 which includes means inside the wall means of the structure to cause the fluid in the intake passage to swirl.

21. A combination as set forth in claim 19 which includes means to cool the fluid from the exhaust passage of the engine.

22. In an induction unit of the character described for installation between the carburetor and the intake passage of an engine, which engine has an exhaust passage and a confined space to receive blowby fluid, the combination of:

a structure for mounting on the engine intake on the downstream of the carburetor, said structure including wall means forming a portion of the intake passage with a closed space surrounding the wall means and with the wall means apertured for fluid flow from the enclosed space into the intake passage;

means united with said structure forming two passages outside of the structure with both passages communicating with the enclosed space, one of the said passages being adapted -for connection to the exhaust passage of the engine, the other passage being adapted for connection to the confined space of the engine;

means united with said structure outside of the structure to cool the exhaust fluid in said one of the passages;

means to divert a portion of the cooled exhaust fluid from said one of the two passages to the other of the two passages of mixture with the fluid therein;

a first valve means in one of said passages to control fluid flow therethrough and adapted to close progressively in response to rising vacuum in the intake passage in a range of magnitudes of vacuum below the magnitude of the vacuum that exists when the engine idles;

a second valve means in the other of the two passages to control fluid flow therethrough and adapted to open progressively in response to rising vacuum in the intake passage in a range of magnitudes of vacuum below the magnitude of the vacuum that exists when the engine idles; and

means to cause the fluid stream in the engine intake to swirl.

23. In a carburetion system for an internal combustion engine having a confined space to receive blowby fluid, an exhaust passage, an intake passage and a carburetor connected to the intake passage, the combination of:

induction structure on the downstream side of the carburetor having inner Wall means forming a longitudinal portion of the intake passage with an enclosed space around the inner wall means and with apertures in the inner wall means for fluid flow from the enclosed space into the intake passage;

Vane means connected with the inner wall means and extending into the intake passage to cause the stream of intake fluid to swirl;

a chamber mounted on the outside of the induction structure and having a relatively large surface exposed to the atmosphere for dissipating heat to the atmosphere, the chamber having an inlet end and an outlet end;

passage means connecting the inlet end of the chamber to the confined space of the engine to receive blowby fluid therefrom;

passage means connecting the inlet end of the chamber to the exhaust passage of the engine to receive exhaust fluid therefrom;

a first passage from the outlet end of the chamber to the enclosed space in the induction structure to convey blowby fluid to the intake passage of the engine;

means inside the chamber to direct a jet of the blowby fluid into the first passage to create a venturi effeet for drawing exhaust fluid from the chamber into the first passage to mix With the blowby fluid and to heat the blowby fluid;

a first valve controlling the first passage and responsive to changes in pressure in the intake passage, the first valve closing progressively in response to rising magnitudes of vacuum in the intake passage in a range of magnitudes below the magnitude of the vacuum at which the engine idles;

a second passage from the chamber to the enclosed space for conveying exhaust fluid to the intake passage of the engine;

a second valve controlling the second passage and responsive to changes in the pressure in the intake passage, the second valve being closed when the vacuum in the intake passage is below the vacuum at which the engine idles and progressively opening in response to rise in the vacuum in the intake passage in a range of magnitudes above the vacuum at which the engine idles.

References Cited by the Examiner UNITED STATES PATENTS 1,350,079 8/1920 Mulkern. 1,895,789 1/1933 Doering. 2,096,526 10/1937 Pratt 123-119 2,720,196 10/1955 Wolf 123119 MARK NEWMAN, Primary Examiner.

KARL J. ALBRECHT, Examiner. 

1. IN A SYSTEM FOR RECYCLING GASEOUS FLUIDS THROUGH THE COMBUSTION ZONE OF AN INTERNAL COMBUSTION ENGINE, WHEREIN PASSAGE MEANS CONVEYS GASEOUS FLUID FROM THE ENGINE TO THE INTAKE OF THE ENGINE, THE IMPROVEMENT COMPRISING: A FIRST VALVE AND A SECOND VALVE OPERATING IN PARALLEL TO CONTROL FLOW THROUGH THE PASSAGE MEANS IN RESPONSE TO CHANGES IN THE PRESSURE IN THE INTAKE, THE FIRST VALVE BEING OPEN AT RELATIVELY LOW VACUUM IN THE INTAKE AND PROGRESSIVELY CLOSING IN RESPONSE TO RISE IN THE VACUUM, THE SECOND VALVE BEING CLOSED AT A RELATIVELY HIGH VACUUM IN THE INTAKE AND PROGRESSIVELY OPENING IN RESPONSE TO RISE IN THE VACUUM. 